Prohibited Noxious Weeds

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The weeds in the prohibited noxious class are those which are known to pose an intolerable economic threat to production, recreation or the general environment, and the degree of infestation is such that eradication is physically and economically feasible.

When prohibited noxious weeds are involved, the Vegetation Management Technicians are obligated to inventory the designated species, to map the locations and issue a notice to destroy. The Vegetation Management Technicians are to advise the Director of Agricultural Services and then monitor the site regularly to ensure that the directives of the notice are carried out. If there is non‑compliance, he will be obliged to contact the Director of Agricultural Services so as to initiate legal action or cause the work to be done and have all costs charged against the land or person involved. Further, continued surveillance by the Vegetation Management Technicians can be anticipated for several years to ensure that there are no recurrences of growth of the weed.

The Weed Control Act stipulates that a person shall destroy a prohibited noxious weed that is on land the person owns or occupies.

Big Head Knapweed

Common Barberry

Common Buckthorn

Common St John's Wort

Diffuse Knapweed

Flowering Rush

Garlic Mustard

Mouse-ear Hawkweed

Nodding Thistle

Orange Hawkweed

Pale Yellow Iris

Plumeless Thistle

Purple Loosestrife

Salt Cedar

Spotted Knapweed

Sulphur Cinquefoil

Autumn Olive

Dodder

Dyer's Woad

Eurasian Water Milfoil

Giant Hogweed

Giant Knotweed

Himalayan Balsam

Hoary Alyssum

Japanese Knotweed

Jointed Goatgrass

Leafy Spurge

Marsh Thistle

Meodusahead

Puncturevine

Red Bartsia

Rush Skeletonweed

Russian Knapweed

Saltlover

Scentless Chamomile

Squarrose Knapweed

Yellow Nutsedge

Yellow Starthistle

For more information on these weeds, please check out the fact sheets from the Alberta Invasive Plants Network.